The Bay Gardener by Dr. Francis Gouin

The Pros and Cons of Clover

It’s Bay-friendly, so it may — or may not — be the lawn you want

A Bay Weekly reader wanted to know how to encourage clover to grow in her lawn because she likes the looks of it. Clover has other benefits. It doesn’t need to be mowed as often, it is very drought resistant and it does not have to be fertilized with nitrogen.

By maintaining a high soil pH and low levels of nitrogen, you can encourage white Dutch clover to grow at the expense of grass. It will take approximately three years to crowd out most of the grasses. You will find that fescue grasses are more tolerant of the clover-favoring conditions than are blue grasses.

First, have the soil tested to make certain the pH is near to above 6.5 with medium to high levels of phosphorus, potassium and magnesium. So as not to encourage grass growth, use only 0-20-20 fertilizer to adjust the phosphorus and potassium levels and dolomitic limestone to add magnesium if needed.

Set the cutting height of your lawnmower to about three inches, and mow the lawn at least twice weekly. Frequent mowing will minimize shading of the clover by grasses.

One of the problems you need to consider in establishing a clover lawn is bees. White Dutch clover flowers profusely and attracts bees. Frequent mowing at the peak of flowering will help to reduce bee populations. Mow in the evening when bee activity is at a minimum.

Should you decide to change your mind after you have established a clover lawn, you will have long-lasting problems. White Dutch clover produces millions of hard seeds that can remain in the ground for years before germinating. You will be fighting clover seedlings for many years should you decide on growing grass again.

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Roots Need Oxygen

Q I need to add a bunch more dirt/soil enhancer to my flower beds, berm them up, if you will. Do I need to dig out all the existing plants before doing so and replant at the higher level. Or at the end of the season, can I dump the dirt on top of them and hope that the plants can poke through the additional soil next spring? Or should I just leave a gully around them and add the dirt now?

–Melinda Zimmerman, Holland Point

A If you are going to raise the bed, you need to dig up and replant the perennials. If you don’t, you will suffocate the roots by piling excess soil over them. Roots need oxygen, and the more soil you place over them, the less oxygen they will receive.